2017-08-18T05:03:57ZZinc deficiency suppresses the development of oral tolerance in ratshttp://hdl.handle.net/2067/2069
Title: Zinc deficiency suppresses the development of oral tolerance in rats
Authors: Finamore, Alberto; Roselli, Marianna; Merendino, Nicolò; Nobili, Fabio; Vignolini, Francesco; Mengheri, Elena
Abstract: Oral tolerance is a speciﬁc immune unresponsiveness to food antigens to prevent hypersensitivity
reactions. We investigated whether zinc deﬁciency affects oral tolerance. Rats were fed a control (C) or zincdeﬁcient (ZD) diet, or pair-fed (PF) to ZD rats for 28 d. Beginning on d 7, rats were administered ovalbumin (OVA)
orally to induce tolerance, or PBS 3 times/wk, and were then immunized by OVA injection. The proliferation of
mesenteric lymph node (MLN) and spleen lymphocytes after in vitro OVA stimulation and the delayed-type
hypersensitivity were higher in OVA-fed ZD than in OVA-fed C rats and not different between OVA- and PBS-fed
ZD rats, indicating a suppression of tolerance. Lymphocyte proliferation did not differ between PF and C rats.
Expressions of cytokines involved in oral tolerance, i.e., interleukin (IL)-4, IL-10 and transforming growth factor- ,
were higher in OVA- than in PBS-fed C rats, but not in ZD rats. Apoptosis was higher in OVA- than in PBS-fed C
rats but not different between OVA- and PBS-fed ZD rats. Inﬂammation and ulcerations that were not present in
ZD rats on d 7 (ZD7
) developed in OVA- or PBS-fed ZD rats. Compared with ZD7
rats, tumor necrosis factor- and
cytokine-induced neutrophil chemoattractant were higher in OVA- and PBS-fed ZD rats, whereas interferon-
increased only in OVA-fed ZD rats. In conclusion, zinc deﬁciency suppresses oral tolerance through dysregulation
of cytokine expression and lack of antigen-speciﬁc clonal deletion. We suggest that abrogation of tolerance may
lead to development of mucosal inﬂammation and damage.
Description: L'articolo è disponibile sul sito dell'editore http://jn.nutrition.org2002-12-31T23:00:00Z